Apparatus for punching and coating printing plates

ABSTRACT

Apparatus for punching and coating printing plates, such as used in the printing of newspapers and magazines. Unprepared plates are moved individually in steps to a punch position where coded slots or holes are punched at the edges of the plate in precise alignment, after which the plate passes between devices for application of a photo sensitive coating. The punched and coated plates are conveyed between air dryers and deposited in a stack in a receptacle. For simplicity and compactness, the plates are guided in a return path on two levels and a single motor drives all of the plates handling means. The apparatus will handle single or double plates of multiple sizes without the need for adjustment.

United States Patent [1 1 Wheaton I APPARATUS FOR PUNCHING AND COATINGPRINTING PLATES [75] Inventor: Robert E. Wheaten, San Diego,

Calif.

[73] Assignee: Copley Press, Inc., La Jolla, Calif. [22] Filed: June 24,1971 [21] Appl. N0.: 156,414

[451 July 3, 1973 2,695,591 11/1954 Bass, Jr. et a1 118/224 FOREIGNPATENTS OR APPLICATIONS 545,119 5/1942 Great Britain 118/40 PrimaryExaminer-John P. McIntosh Attorney-Carl R. Brown et a1.

[5 7] ABSTRACT Apparatus for punching and coating printing plates, suchas used in the printing of newspapers and magazines. Unprepared platesare moved individually in steps to a punch position where coded slots orholes are punched at the edges of the plate in precise alignment, afterwhich the plate passes between devices for application of a photosensitive coating. The punched and coated plates are conveyed betweenair dryers and deposited in a stack in a receptacle. For simplicity andcompactness, the plates are guided in a return path on two levels and asingle motor drives all of the plates handling means. The apparatus willhandle single or double plates of multiple sizes without the need foradjustment.

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20 ROBERT E. WHEATON BY XL mm ATTORNEYS APPARATUS FOR PUNCHING ANDCOATING PRINTING PLATES BACKGROUND OF THE INVENTION In preparingprinting plates, the photo sensitive coating in which the printed matteris produced is applied prior to exposing the plate to register an image.Also, a set of coded slots or holes must be punched in the plate foralignment and registration on the printing roll, cylinder or bed. Thetwo operations are usually carried out separately and involveconsiderable handling of the plates, with the possibility of damage tothe plates and injury to the handler, since the plates are normally ofvery thin metal.

SUMMARY OF THE INVENTION In the apparatus described herein, plates areplaced on a conveyor and are moved individually to a punch station,where all of the slots or holes are punched simultaneously. Alignmentmeans and retractable stops hold the plate while being punched. Eachplate then passes between coating rolls or brushes which apply a photosensitive coating to at least one side, the plate then being guided in areturn path to a second conveyor below the punch station. The lowerconveyor moves the plate between air blast dryers and deposits the platein a receptacle, all without handling. Both conveyors and the coatingrolls are driven continuously by a single motor, the plates being heldwhere necessary by the retractable stops. The return path arrangementwith upper and lower processing stations makes the apparatus compact,and the coated plates are afforded good protection. Control can beperformed manually, or automatically in sequence, the mechanism beingreadily adaptable. The apparatus is constructed on a simple open frame,with all parts accessible for servicing.

The primary object of this invention, therefore, is to provide a new andimproved apparatus for punching and coating printing plates.

It is another object of this invention to provide a new and improvedapparatus which punches, coats and drys printing plates in sequence.

. It is another object of this invention to provide a new and improvedapparatus which punches and coats printing plates in sequence, withoutthe need for handling between initial placement on the apparatus anddelivery into a collection receptacle.

It is another object of this invention to provide a new and improvedpunching and coating apparatus capable of handling single or doublesized plates of multiple sizes.

It is another object of this invention to provide a new and improvedpunching and coating apparatus which is compact and simple inconstruction and operation.

Other objects and many advantages of this invention will become apparentupon a reading of the following detailed description and an examinationof the drawings wherein like reference numerals designate like partsthroughout and in which:

FIG. I is a side elevation view of the complete apparatus.

FIG. 2 is an enlarged top plan view of the punching and coatingstations.

FIG. 3 is a view of a typical punched plate.

FIG. 4 is a sectional view taken on line 4-4 of FIG. 2.

FIG. 5 is an enlarged sectional view taken on line 5-5 of FIG. 4.

DESCRIPTION OF THE PREFERRED EMBODIMENT The apparatus is constructed ona simple open frame 10, the structure of which may vary. As illustrated,the frame includes longitudinal side members 12 joined at opposite endsby cross members 14 in a rigid rectangular structure, which is supportedon pairs of end legs 16 and 18, and intermediate support 20 andintermediate leg 22. Horizontal bracing members, such as 24 and 26, areused where necessary.

Secured on top of side members 12 are transverse cross bars 28, whichsupport a flat loading table 30 and a bed plate 32 in end to endcoplanar relation. Extending longitudinally around the bed plate andloading table is an upper conveyor 34, comprising a plurality of thinendless belts 36 in spaced parallel alignment. The belts 36 aresupported between pulleys 38 on a shaft 40 and pulleys 41 on a shaft 42.Shaft 40 is journalled in bearings 44 on side members 12 adjacent theouter or entry end of loading table 30. Shaft 42 is similarly journalledin bearings 46 on the side members adjacent the exit end of bed plate32. The upper surfaces of the loading table and bed plate havelongitudinal grooves 48 for the upper reaches of belts 36, as in FIG. 5.A printing plate 50 is normally carried on the belts 36 slightly abovethe surfaces of the table and bed plate, with minimum contact with itssupport to reduce friction and avoid scratching. The grooves 48 allowthe plate 50 to be pressed down on the supporting surface momentarilywhile being punched. It should be recognized that the upper surface ofthe loading table and bed plate may have a flat surface without grooves48. The belts 36 would have a flat rectangular configuration and a thinthickness that would support the printing plate 50 above the uppersurface of the bed plate. The printing plate 50 is sufficiently flexiblethat its edges can be bent down to be punched by punches 6].

Along opposite sides of bed plate 32 are parallel guide rails 52 and 54,with undercut channels 56 and 58, respectively, to receive the printingplate 50 with sliding fit. Vertical and horizontal clearance in thechannels is not critical, limitation of side to side alignment being theimportant factor as controlled by guide pin and guide roller 72. Mountedon top of guide rails 52 and 54 are punches 60, which are conventionalunits actuated by air or fluid pressure or other such means. The numberand spacing of the punches and shape of the punch bits 61 will depend onthe arrangement of locating pins on the drum or bed to which theprinting plate is to be attached. A typical plate 50, shown in FIG. 3,has a circular hole 62 and two elongated notches 64 along one edge, anda slot 65 at the other edge. The plate 50 is shown as a single pageplate, but the length of the guide rails and the arrangement of punchesis sufficient to accommodate multiple sized plates.

A plate is held in position for punching by a pair of stop pins 66,which project upwardly from the bed plate 32 to engage the forward edgeof the plate. The stop pins are made retractable by means of actuators68, operated by air pressure, solenoids or the like. One side edge ofthe plate bears against an alignment pin 70 fixed in the bed plate andis held by a spring loaded roller 72 on the other side edge. On theloading table 30, a plate is held in readiness against stop pins 74,which are retracted by actuators 76, and is aligned by a fixed pin 78 atone side for entry between the guide rails 52 and 54.

A motor 80 is mounted in frame and, through a gear box 82, drives ashaft 84 journalled between bearings 86 on end legs 16. Conveyor 34 isdriven continuously by a belt drive 88 between shafts 84 and 42, theretractable stop pins being used to hold the plates momentarily at theirrespective stations.

Fixed to frame 10 at the exit end of the upper conveyor 34 is a coatingunit 90, having a coating roller 92 rotatably mounted between bearingbrackets 94. The coating roller is partially immersed in a reservoir 96containing liquid sensitizing material 98, and is driven by a belt drive100 from shaft 84. Above the coating roller is a pressure roller 102,journalled in bearing bldcks 104, which are vertically adjustable onbearing brackets 94 by means of screws 106. A plate 50 leaving the upperconveyor is drawn between rollers 92 and 102, and the underside iscoated with sensitized material. The coated plate is turned by curvedguides 108 and drops down to a lower conveyor 110, with the coatedsurface now uppermost.

Lower conveyor 110 is similar in construction to the upper conveyor andcomprises a plurality of thin endless belts l12, stretched betweenpulleys 114 and 116. The pulleys 114 are mounted on a shaft 118 rotatingin bearings 120 on the legs 16, and pulleys 116 are on a shaft 122carried in bearings 124 on legs 22. Immediately below shaft 84 is aparallel shaft 126 in bearings 128, the two shafts being coupled bygears 130 and 132 to rotate in opposite directions. A speed reducingbelt drive 134 from shaft 126 to shaft 118 drives the lower conveyor atabout half the speed and in the opposite direction to the upperconveyor.

The lower conveyor caries the plates between a pair of air blowers 136and 138 mounted on legs 20, or other convenient supporting structure.Upper blower 136 has an outlet 140 directed downwardly on the passingplate, and lower blower 138 has an upwardly directed outlet 142. Heat isnot necessary, the moving air at room temperature being sufficient todry the very thin coating on the plate, and the reduced speed of thelower conveyor ensuring ample drying time. The air from the lower bloweropposes the upper blower and the plate effectively floats off the lowerconveyor and drops lightly into a receptacle 144, which is mounted on aplatform 146 at the exit end of the lower conveyor.

The various mechanisms can be controlled manually, but are preferablyactuated automatically in sequence. The actual control and timing systemwill depend on the type of punches and stop pin actuators used, suitableapparatus being well known. For automatic operation, some means isnecessary to time the stop pin operation. This can be accomplished by adetector 148, such as a photocell, insert in the loading table 30 justahead of stop pins 74. When stop pins 66 and 74 are retracted by thesequencing mechanism, the punched plate moves forward through thecoating unit and the next plate advances from the loading table, drivenby the continuously moving upper conveyor. Detector 148 senses thepassing of the plate from the loading table and initiates extension ofboth sets of stop pins to stop the plates again in their respectivepositions. The cycle of time ofa plate through the punch position would,of

course, be sufficient to prevent bunching of coated plates on the slowermoving lower conveyor.

By returning the plates and drying and stacking them in the lowerportion of the apparatus, the overall size of the structure is greatlyreduced. The continuously running conveyors and coating roller avoid thenecessity for periodic starting and stopping of the main drive means andmakes it feasible to use a single motor for the complete plate handlingdrive. The open frame structure makes all parts readily accessible andthe only regular maintenance required in normal operation is thereplenishment of coating liquid in reservoir 96.

Having described my invention, I now claim:

1. Apparatus for punching and coating printing plates, comprising:

a frame;

a substantially flat bed plate and a coplanar loading table on top ofsaid frame;

a first conveyor for moving printing plates successively from saidloading table to said bed plate;

punch means mounted on said bed plate for punching edges of eachprinting plate in a predetermined pattern;

a coating unit mounted on said frame to receive a printing plate fromsaid conveyor, said coating unit having means for applying an imagereceiving coating to at least one surface of a printing plate;

a second conveyor mounted on said frame;

guide means for directing printing plates from said coating unit to saidsecond conveyor;

drying means mounted to direct airflow over printing plates carried onsaid second conveyor,

each of said conveyors has a plurality of thin endless belts in spacedparallel relation, the belts of said first conveyor supporting aprinting plate above said bed plate,

and said bed plate has grooves into which said endless belts can bedepressed.

2. Apparatus according to claim 1, wherein said coating unit has upperand lower rollers positioned to receive printing plates therebetween,and a liquid containing reservoir in which said lower roller isimmersed, at least one of said rollers having continuous drive meansconnected thereto.

3. Apparatus according to claim 1, wherein said first conveyor iscontinuously driven, said bed plate and said loading table havingselectively retractable stop means thereon for holding printing platesmomentarily in punching and loading positions, respectively.

4. Apparatus according to claim 3, wherein said drying means includes anair blower mounted above said second conveyor.

5. Apparatus according to claim 4, wherein said drying means furtherincludes an air blower mounted below said second conveyor.

6. Apparatus according to claim 5, wherein said second conveyor iscontinuously driven at a speed slower than that of the first conveyor.

7. Apparatus for punching and coating printing plates, comprising:

a frame;

a substantially flat bed plate and a coplanar loading table on top ofsaid frame;

a first conveyor for moving printing plates successively from saidloading table to said bed plate;

punch means mounted on said bed plate for punching edges of eachprinting plate in a predetermined pattern;

a coating unit mounted on said frame to receive a printing plate fromsaid conveyor, said coating unit having means for applying an imagereceiving coating to at least one surface of a printing plate;

a second conveyor mounted on said frame;

guide means for directing printing plates from said coating unit to saidsecond conveyor;

drying means mounted to direct airflow over printing plates carried onsaid second conveyor,

and guide rails on said bed plate, with channels to receive a printingplate therebetween, said punch

1. Apparatus for punching and coating printing plates, comprising: aframe; a substantially flat bed plate and a coplanar loading table ontop of said frame; a first conveyor for moving printing platessuccessively from said loading table to said bed plate; punch meansmounted on said bed plate for punching edges of each printing plate in apredetermined pattern; a coating unit mounted on said frame to receive aprinting plate from said conveyor, said coating unit having means forapplying an image receiving coating to at least one surface of aprinting plate; a second conveyor mounted on said frame; guide means fordirecting printing plates from said coating unit to said secondconveyor; drying means mounted to direct airflow over printing platescarried on said second conveyor, each of said conveyors has a pluralityof thin endless belts in spaced parallel relation, the belts of saidfirst conveyor supporting a printing plate above said bed plate, andsaid bed plate has grooves into which said endless belts can bedepressed.
 2. Apparatus according to claim 1, wherein said coating unithas upper and lower rollers positioned to receive printing platestherebetween, and a liquid containing reservoir in which said lowerroller is immersed, at least one of said rollers having continuous drivemeans connected thereto.
 3. Apparatus according to claim 1, wherein saidfirst conveyor is continuously driven, said bed plate and said loadingtable having selectively retractable stop means thereon for holdingprinting plates momentarily in punching and loading positions,respectively.
 4. Apparatus according to claim 3, wherein said dryingmeans includes an air blower mounted above said second conveyor. 5.Apparatus according to claim 4, wherein said drying means furtherincludes an air blower mounted below said second conveyor.
 6. Apparatusaccording to claim 5, wherein said second conveyor is continuouslydriven at a speed slower than that of the first conveyor.
 7. Apparatusfor punching and coating printing plates, comprising: a frame; asubstantially flat bed plate and a coplanar loading table on top of saidframe; a first conveyor for moving printing plates successively fromsaid loading table to said bed plate; punch means mounted on said bedplate for punching edges of each printing plate in a predeterminedpattern; a coating unit mounted on said frame to receive a printingplate from said conveyor, said coating unit having means for applying animage receiving coating to at least one surface of a printing plate; asecond conveyor mounted on said frame; guide means for directingprinting plates from said coating unit to said second conveyor; dryingmeans mounted to direct airflow over printing plates carried on saidsecond conveyor, and guide rails on said bed plate, with channels toreceive a printing plate therebetween, said punch means being mounted onsaid guide rails.
 8. Apparatus according to claim 7, and including stopmeans on said bed plate for holding a printing plate in aligned punchingposition.
 9. Apparatus according to claim 8, wherein said first conveyoris continuously operable, said stop means being selectively retractableto release each printing plate after punching.
 10. Apparatus accordingto claim 9, and including further selectively retractable stop means onsaid loading table adjacent said bed plate, for holding a printing platein readiness for advancement to the punching position.